diff --git a/meow/index.d.ts b/meow/index.d.ts
index d687f65611..fe208c83f5 100644
--- a/meow/index.d.ts
+++ b/meow/index.d.ts
@@ -22,7 +22,7 @@ declare namespace meow {
         flags: { [name: string]: any };
         pkg: any;
         help: string;
-        showHelp(code: number): void;
+        showHelp(code?: number): void;
     }
 
 }